IEC/IEEE 62395-1:2024
(Main)Electrical resistance trace heating systems for industrial and commercial applications - Part 1: General and testing requirements
Electrical resistance trace heating systems for industrial and commercial applications - Part 1: General and testing requirements
IEC/IEEE 62395-1:2024 specifies requirements for electrical resistance trace heating systems and includes general test requirements.
This first edition cancels and replaces the second edition published in 2013. This edition constitutes a technical revision.
This edition includes the following significant technical changes, apart from general revisions of IEC 62395-1 and harmonization with IEEE 515 [1] and IEEE 515.1 [2], with respect to the previous edition:
a) Added control and monitoring requirements for fire sprinkler systems and safety showers.
b) Provided a supplemental ice bath method for verification of rated output.
c) Provided constructional and type test requirements for glands used to terminate heating devices to an exposed enclosure.
Systèmes de traçage par résistance électrique pour applications industrielles et commerciales - Partie 1: Exigences générales et d'essai
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IEC/IEEE 62395-1 ®
Edition 1.0 2024-06
INTERNATIONAL
STANDARD
colour
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Electrical resistance trace heating systems for industrial and commercial
applications –
Part 1: General and testing requirements
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IEC/IEEE 62395-1 ®
Edition 1.0 2024-06
INTERNATIONAL
STANDARD
colour
inside
Electrical resistance trace heating systems for industrial and commercial
applications –
Part 1: General and testing requirements
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 25.180.10 ISBN 978-2-8322-9002-6
– 2 – IEC/IEEE 62395-1:2024 © IEC/IEEE 2024
CONTENTS
FOREWORD . 5
INTRODUCTION . 7
1 Scope . 8
2 Normative references . 8
3 Terms and definitions . 9
4 General requirements . 14
4.1 General . 14
4.2 Electrically conductive covering . 15
4.3 Electrical circuit protection requirements for branch circuits . 15
4.4 Temperature requirements . 15
4.4.1 General . 15
4.4.2 Stabilized design . 15
4.4.3 Controlled design . 15
4.4.4 Controls and monitoring for fire sprinkler systems and safety showers . 16
5 Testing . 16
5.1 Type tests – General . 16
5.2 Type tests – All applications . 19
5.2.1 Dielectric test . 19
5.2.2 Electrical insulation resistance test . 20
5.2.3 Flammability test . 20
5.2.4 Room temperature impact test . 23
5.2.5 Minimum temperature impact test . 25
5.2.6 Deformation test . 26
5.2.7 Cold bend test . 27
5.2.8 Water resistance test . 28
5.2.9 Integral components resistance to water test . 28
5.2.10 Verification of rated output . 29
5.2.11 Thermal stability of electrical insulating material . 33
5.2.12 Thermal performance test . 33
5.2.13 Maximum sheath temperature . 35
5.2.14 Verification of start-up current . 46
5.2.15 Verification of the electrical resistance of the electrically conductive
covering . 46
5.2.16 Test for heating device / heating device set glands - General . 47
5.2.17 Connection Integrity (integral components) . 48
5.3 Type tests – Additional tests for outdoor exposed surface heating
installations without thermal insulation . 50
5.3.1 Verification of rated output . 50
5.3.2 Determination of maximum sheath temperature . 50
5.3.3 Increased moisture resistance test . 50
5.3.4 UV and condensation test . 51
5.3.5 Resistance to cutting test . 51
5.3.6 Abrasion test . 51
5.3.7 Tension test . 52
5.3.8 Rail system voltage spike test . 52
5.3.9 Rail system over-voltage test . 53
5.4 Type tests – Additional tests and test modifications for embedded heating
applications. 53
5.4.1 Verification of rated output . 53
5.4.2 Determination of maximum sheath temperature . 53
5.4.3 Resistance to cutting test . 53
5.4.4 Flammability test . 53
5.5 Type tests – Additional tests for applications of trace heaters internal to
conduit and piping . 53
5.5.1 Verification of rated output . 53
5.5.2 Determination of maximum sheath temperature . 53
5.5.3 Increased moisture resistance test . 54
5.5.4 Pull-strength test . 54
5.6 Type tests – Additional requirements for sprinkler systems . 55
5.6.1 Normal and abnormal operation test . 55
5.6.2 Normal operation test with controller . 55
5.6.3 Abnormal operation test with controller malfunctioning. 58
5.6.4 Abnormal operation test without controller . 58
5.6.5 Testing for control systems for fire sprinkler systems . 58
5.7 Routine tests . 58
5.7.1 Dielectric test . 58
5.7.2 Verification of rated output . 59
6 Marking . 59
6.1 General . 59
6.2 Product markings . 59
7 Installation instructions . 60
Annex A (informative) Determination of test samples for type testing . 62
Bibliography . 64
Figure 1 – Flammability test . 22
Figure 2 – Example of room temperature impact test apparatus . 24
Figure 3 – Example of minimum temperature impact test apparatus . 26
Figure 4 – Cold bend test . 27
Figure 5 – Integral components resistance to water test . 28
Figure 6 – Verification of rated output . 32
Figure 7 – Verification of sheath temperatures utilizing pipe sculpture fixture . 37
Figure 8 – Verification of sheath temperatures utilizing plate fixture . 39
Figure 9 – Verification of sheath temperatures utilizing plate fixture with serpentined
sample . 40
Figure 10 – Plate fixture with two samples crossed over . 41
Figure 11 – Plate fixture with a single sample crossed over . 42
Figure 12 – Maximum sheath temperature using the product approach . 46
Figure 13 – Gland temperature measurement – location of thermocouples . 48
Figure 14 – Typical splice firm attachment apparatus . 49
Figure 15 – Abrasion test . 52
Figure 16 – Sprinkler system temperature control test – branch line arrangement . 56
– 4 – IEC/IEEE 62395-1:2024 © IEC/IEEE 2024
Figure 17 – Sprinkler system temperature control test – branch line – alternative
arrangement . 57
Figure 18 – Sprinkler system temperature control test – supply pipe arrangement . 57
Table 1 – Trace heater and surface heater types and related attributes . 17
Table 2 – Applicable tests for trace heaters, surface heaters, and integral components,
by trace heater and surface heater type . 18
Table 3 – Test voltages for the dielectric test . 19
Table 4 – Applicable test subclauses for the verification of rated output . 29
Table 5 – Pulling forces for strain relief test . 47
Table 6 – Product marking . 60
Table A.1 – Determination of test samples . 62
ELECTRICAL RESISTANCE TRACE HEATING SYSTEMS
FOR INDUSTRIAL AND COMMERCIAL APPLICATIONS –
Part 1: General and testing requirements
FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
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of infringement of such rights, is entirely their own responsibility.
– 6 – IEC/IEEE 62395-1:2024 © IEC/IEEE 2024
IEC/IEEE 62395-1 has been prepared by IEC technical committee 27: Industrial electroheating
and electromagnetic processing, in cooperation with Petroleum & Chemical Industry Committee
of the IEEE Industrial Applications Society, under the IEC/IEEE Dual Logo Agreement between
IEC and IEEE. It is an International Standard.
This document is published as an IEC/IEEE Dual Logo standard.
This first edition cancels and replaces the second edition published in 2013. This edition
constitutes a technical revision.
This edition includes the following significant technical changes, apart from general revisions
of IEC 62395-1 and harmonization with IEEE 515 [1] and IEEE 515.1 [2], with respect to the
previous edition:
a) Added control and monitoring requirements for fire sprinkler systems and safety showers.
b) Provided a supplemental ice bath method for verification of rated output.
c) Provided constructional and type test requirements for glands used to terminate heating
devices to an exposed enclosure.
The text of this International Standard is based on the following IEC documents:
Draft Report on voting
27/1182A/FDIS 27/1186/RVD
Full information on the voting for its approval can be found in the report on voting indicated in
the above table.
The language used for the development of this International Standard is English.
This document was drafted in accordance with the rules given in the ISO/IEC Directives, Part 2,
available at www.iec.ch/members_experts/refdocs. The main document types developed by IEC
are described in greater detail at www.iec.ch/publications/.
A list of all parts in the IEC 62395 series, published under the general title Electrical resistance
trace heating systems for industrial and commercial applications, can be found on the IEC
website.
The IEC Technical Committee and IEEE Technical Committee have decided that the contents
of this document will remain unchanged until the stability date indicated on the IEC website
under webstore.iec.ch in the data related to the specific document. At this date, the document
will be
• reconfirmed,
• withdrawn, or
• revised.
IMPORTANT – The "colour inside" logo on the cover page of this document indicates
that it contains colours which are considered to be useful for the correct understanding
of its contents. Users should therefore print this document using a colour printer.
___________
Numbers in square brackets refer to the Bibliography.
INTRODUCTION
IEC/IEEE 62395-1 provides the essential requirements and testing appropriate to electrical
resistance trace heating equipment used in industrial and commercial applications. While some
of this work already exists in national or international standards, this document has collated
much of this existing work and added considerably to it.
IEC/IEEE 62395-2 provides detailed recommendations for the system design, installation and
maintenance of electric trace heating systems in industrial and commercial applications.
It is the objective of the IEC/IEEE 62395 series that, when in normal use, electrical trace heating
systems operate safely under their defined conditions of use, by
a) employing heaters of the appropriate construction and meeting the test criteria detailed in
IEC/IEEE 62395-1. The construction includes a metallic sheath, braid, screen or equivalent
electrically conductive covering;
b) operating at safe temperatures when designed, installed, and maintained in accordance with
IEC/IEEE 62395-2.
c) having at least the minimum levels of overcurrent and earth-fault protection required in
IEC/IEEE 62395-1 and IEC/IEEE 62395-2.
– 8 – IEC/IEEE 62395-1:2024 © IEC/IEEE 2024
ELECTRICAL RESISTANCE TRACE HEATING SYSTEMS
FOR INDUSTRIAL AND COMMERCIAL APPLICATIONS –
Part 1: General and testing requirements
1 Scope
This part of IEC/IEEE 62395 specifies requirements for electrical resistance trace heating
systems and includes general test requirements.
This document pertains to trace heating systems that can comprise either factory-fabricated or
field-assembled (work-site) units, and which can be series and parallel trace heaters or surface
heaters (heater pads and heater panels) that have been assembled and/or terminated in
accordance with the manufacturer's instructions.
This document also includes requirements for termination assemblies and control methods used
with trace heating systems.
This document provides the essential requirements and testing appropriate to electrical
resistance trace heating equipment used in industrial and commercial applications. The
products complying with this document are intended to be installed by persons who are suitably
trained in the techniques required and that only trained personnel carry out especially critical
work, such as the installation of connections and terminations. Installations are intended to be
carried out under the supervision of a qualified person who has undergone supplementary
training in electric trace heating systems.
This document does not include or provide for any applications in potentially explosive
atmospheres.
This document does not cover induction, impedance or skin effect heating.
Trace heating systems are grouped into different types of applications and the different
conditions found during and after installation necessitate different requirements for testing.
Trace heating systems are usually for a specific type of installation or application. The product
type grouping, applications and product attributes are indicated in Table 1.
NOTE Trace heating systems intended for use in explosive atmospheres are the subject of IEC/IEEE 60079-30-1
[3] and IEC/IEEE 60079-30-2 [4].
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies.
For undated references, the latest edition of the referenced document (including any
amendments) applies.
IEC 60519-1, Safety in installations for electroheating and electromagnetic processing – Part 1:
General requirements
IEC 60529, Degrees of protection provided by enclosures (IP Code)
IEC 60695-11-3:2012, Fire hazard testing – Part 11-3: Test flames – 500 W flames – Apparatus
and confirmational test methods
IEC/IEEE 62395-2:2024, Electrical resistance trace heating systems for industrial and
commercial applications – Part 2: Application guide for system design, installation and
maintenance
ISO 7240-2:2017, Fire detection and alarm systems – Part 2: Fire detection control and
indicating equipment
ANSI/UL 864, Standard for Control Units and Accessories for Fire Alarm Systems – Control and
Indicating Equipment
ASTM D 5025-20, Standard Specification for Laboratory Burner Used for Small-Scale Burning
Tests on Plastic Materials
ASTM G155-21, Standard practice for operating xenon arc light apparatus for exposure of non-
metallic materials
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO, IEC and IEEE maintain terminology databases for use in standardization at the following
addresses:
• IEC Electropedia: available at https://www.electropedia.org/
• ISO Online browsing platform: available at https://www.iso.org/obp
• IEEE Standards Dictionary Online: available at http://dictionary.ieee.org
NOTE 1 General definitions are given in the International Electrotechnical Vocabulary, IEC 60050 (all parts) [5].
Terms relating to industrial electroheat are defined in IEC 60050-841 [6].
NOTE 2 The terms defined in this Clause 3 are used both in IEC/IEEE 62395-1 and IEC/IEEE 62395-2.
3.1
ambient temperature
temperature surrounding the object under consideration
Note 1 to entry: Where trace heaters or surface heaters are enclosed in thermal insulation, the ambient temperature
is the temperature exterior to such thermal insulation.
3.1.1
maximum ambient temperature
highest specified ambient temperature
3.1.2
minimum ambient temperature
lowest specified ambient temperature
Note 1 to entry: Heat-loss calculations in IEC 62395-2 are based on the minimum ambient temperature.
3.2
branch circuit
portion of the wiring installation between the overcurrent device protecting the circuit and the
trace heater(s) or surface heater(s)
3.3
cold lead
electrically insulated conductor or conductors used to connect a trace heater or surface heater
to the branch circuit and designed so that it does not produce significant heat
– 10 – IEC/IEEE 62395-1:2024 © IEC/IEEE 2024
3.4
connection
termination or splice used to attach trace heaters or surface heaters to power wiring or to
connect sections of these devices
3.5
dead-leg
segment of process piping segregated from the normal flow pattern for the purpose of providing
a heat loss reference
3.6
design loading
minimum power that meets the design requirements, in the specified adverse conditions
(minimum ambient and maximum wind velocity), after voltage and resistance tolerances and
appropriate safety factors have been considered
[SOURCE: IEC/IEEE 60079-30-1:2015, 3.6]
3.7
electrically conductive covering
metallic braid, metallic sheath, or alternative covering with sufficient conductivity so that, when
bonded to ground, it will allow a ground fault protective device to operate under a fault condition
3.8
end termination
termination, which can be heat producing, applied to a trace heater at the end opposite to that
where the power is supplied
3.9
factory-fabricated unit
trace heater unit or set or surface heater unit or set, including the necessary terminations and
connections, assembled by the manufacturer
3.10
field-assembled unit
trace heaters or surface heaters supplied unterminated with terminating components to be
assembled at the work site
3.11
heat loss
energy flow from a workpiece, pipe, vessel or equipment to its surroundings
3.12
heat sink
part that conducts and dissipates heat away from a workpiece
Note 1 to entry: Typical heat sinks are pipe shoes, pipe supports and items of large mass such as valve actuators
or pump bodies.
3.13
heat transfer aids
thermally conductive materials, such as metallic foils or heat transfer compounds used to
increase the heat-transfer efficiency from trace heaters or surface heaters to the workpiece
3.14
heater pad
surface heater, comprising series or parallel connected elements having sufficient flexibility to
conform to the shape of the surface to be heated
3.15
heater panel
non-flexible surface heater, comprising series or parallel connected elements fabricated to
conform to the general shape of the surface to be heated
3.16
heating device
trace heater or surface heater
3.17
heating device set
heating device assembled with the associated parts necessary to connect it to a source of
electrical supply
3.18
integral component
component such as a heat shrink termination, a cold lead connection, a moulded end seal or a
splice, which conforms to the general shape of the trace heater or surface heater and is exposed
to the same environment as the trace heater or surface heater, which can be factory-fabricated
or field-assembled, and which is not intended to be re-used in the event of a repair or
modification
3.19
low risk of mechanical damage
installations and applications where only lower levels of impact and deformation are expected
to occur
3.20
maximum continuous exposure temperature (trace heater de-energized)
highest allowable continuous temperature to which the trace heating system can be exposed as
declared by the manufacturer
3.21
maximum intermittent exposure temperature
highest allowable intermittent temperature to which a trace heater can be exposed, as declared
by the manufacturer
3.22
maximum maintain temperature
specified maximum workpiece or process temperature the trace heater can maintain as declared
by the manufacture
3.23
maximum continuous operating temperature
specified maximum workpiece temperature, the trace heater, can operate continuously when
energized as declared by the manufacturer
3.24
maintain temperature
specified temperature of a workpiece or process that the trace heaters shall be able to maintain
3.25
maximum sheath temperature
maximum temperature of the outermost continuous covering of the trace heater or surface
heater
– 12 – IEC/IEEE 62395-1:2024 © IEC/IEEE 2024
3.26
maximum withstand temperature
maximum continuous exposure temperature or the maximum intermittent exposure temperature
(energized or de-energized) whichever is higher, as declared by the manufacturer
3.27
minimum installation temperature
minimum temperature at which the trace heating system can be handled and installed
3.28
MI trace heater
mineral insulated metal sheathed trace heater typically containing one or more heating
conductors
3.29
operating voltage
actual voltage applied to the trace heater or surface heater when in service
3.30
outdoor exposure
exposure to outdoor conditions of ultraviolet light and moisture
3.31
overjacket
continuous layer of material applied over the trace heater or surface heater to provide
mechanical or environmental protection
3.32
parallel trace heater
heating elements that are electrically connected in parallel, either continuously or in zones, so
that the power output per lineal length is maintained, irrespective of any change in length for
the continuous type or for any number of discrete zones
3.33
rated output
total power or the power per unit length or power per unit surface area of the trace heater or
surface heater at rated voltage, temperature, and length or area
3.34
rated voltage
voltage assigned by the manufacturer to which operating and performance characteristics of
trace heaters or surface heaters are referred
3.35
routine test
test that is carried out by the manufacturer of the trace heater or surface heater on all trace
heaters or surface heaters during or after the production process
3.36
series trace heater
heating elements electrically connected in series with a single current path and with a specific
resistance at a given temperature for a given length
3.37
sheath
uniform and continuous metallic or non-metallic covering enclosing components of the trace
heater or surface heater to provide protection against influence from the surroundings (e.g.,
corrosion, moisture, abrasion, etc.)
Note 1 to entry: See overjacket (3.31).
3.38
sheath temperature
temperature of the outermost continuous covering (braid, sheath, or overjacket) that can be
exposed to the surrounding environment
3.39
stabilized design
design method where the temperature of the trace heater or surface heater will, by design and
use, stabilize below the limiting temperature, under the most unfavourable conditions, without
the need for a protective system to limit the temperature
3.40
start-up current
current of a trace heater or surface heater following energization
3.41
surface heater
heater pad or heater panel
3.42
surface heater unit
surface heater suitably terminated in conformity with the manufacturer's instructions
3.43
system documentation
information provided by the trace heater manufacturer to allow satisfactory understanding,
installation and safe use of the trace heating system
3.44
tee
electrical connection of trace heaters, in series or in parallel, to accommodate a branch or a
branch circuit
3.45
temperature controller
device or combination of devices incorporating a means of sensing temperature and of
controlling the energy supplied to the trace heater or surface heater
3.46
temperature sensor
device designed to respond to temperature providing an electrical signal or mechanical
operation
3.47
thermal insulation
material having air- or gas-filled pockets, voids, or heat reflecting surfaces that, when properly
applied, retards the transfer of heat
– 14 – IEC/IEEE 62395-1:2024 © IEC/IEEE 2024
3.48
trace heater
device of linear geometry designed for the purpose of producing heat on the principle of
electrical resistance
3.49
trace heater unit
trace heater suitably terminated in conformity with the manufacturer's instructions
3.50
trace heating
utilization of trace heaters or surface heaters as well as support components, designed for the
purpose of producing heat through heating elements electrically connected in series or in
parallel, used to maintain or raise temperatures of piping, tanks and other surfaces
3.51
type test
conformity test made on one or more items representative of the production
[SOURCE: IEC 60050-151:2001, 151-16-16]
3.52
weather barrier
material that, when installed on the outer surface of thermal insulation, protects the thermal
insulation from water or other liquids, from physical damage caused by ice pellets, wind or
mechanical abuse and from deterioration caused by solar radiation or atmospheric
contamination
3.53
workpiece
object to which a trace heater or surface heater is applied
4 General requirements
4.1 General
Electrical resistance trace heating systems within the scope of this document shall be designed
and constructed so as to help ensure electrical, thermal and mechanical durability and reliable
performance such that, in normal use, they pose no danger to the user or the surroundings.
Trace heaters which are identified for use only in areas with a low risk of mechanical damage
are subjected to a reduced load in the impact tests in 5.2.4 and 5.2.5 and a reduced force in
the deformation test in 5.2.6 and shall be clearly marked as specified in Clause 7.
Trace heaters and surface heaters can be supplied with additional mechanical protection to
meet the requirements of this document if they are supplied as an integral assembly
(prefabricated) and shall be marked as required by Clause 7, item g).
Trace heating equipment intended for use in contact with potable water shall be constructed of
materials that meet relevant toxicity requirements.
Trace heaters and surface heaters temperature ratings that are required to conduct the type
test in this document, shall be stated and controlled by the trace heater manufacturer in their
documentation and published in their literature. The trace heater manufacturer shall provide
documentation of the specification of non-metallic materials on which the mechanical strength
and the electrical insulation depend (between the heater and other conductive parts) which shall
include identification of the material type.
4.2 Electrically conductive covering
Trace heaters and surface heaters shall be provided with an evenly distributed electrically
conductive covering which shall cover at least 70 % of the surface. Surface heating units shall
be constructed such that the electrically conductive covering shall be opposite the surface to
be heated.
4.3 Electrical circuit protection requirements for branch circuits
The minimum requirements for trace heating systems are:
a) a means of isolating all live conductors from the supply;
b) over-current protection provided for each branch circuit;
c) a means of protecting against earth-faults by disconnecting all live conductors.
The trace heater or surface heater branch circuit electrical protection shall be capable of
interrupting earth faults, as well as short-circuit faults. An earth-fault protective device or a
controller with earth-fault interruption capability shall be used. The preferred trip level is nominal
30 mA or 30 mA above any inherent capacitive leakage characteristic of the heater as specified
by the trace heater or surface heater supplier. These devices are intended for use in conjunction
with circuit overcurrent protection. Where conditions of maintenance and supervision help
ensure that only qualified persons will service the installed systems and continued circuit
operation is necessary for the safe operation of the equipment or processes, earth-fault
detection without interruption is acceptable if alarmed in a manner assuring an acknowledged
response.
4.4 Temperature requirements
4.4.1 General
A trace heating system shall be designed so that under all conditions that can reasonably be
foreseen, the surface temperature of the trace heater or surface heater does not exceed its
maximum withstand temperature or any maximum system temperature ratings. This shall be
achieved by a stabilized design or controlled design. In the design process of a system, the
temperatures that occur have to be considered. All components, for example terminals or glands
used with the trace heaters, have to resist the adjacent temperatures.
4.4.2 Stabilized design
Stabilized design applications, in which the maximum surface temperature of the trace heater
or surface heater is determined without thermostatic control, shall employ either the systems
approach specified in 5.2.13.2 or the product approach specified in 5.2.13.3.
4.4.3 Controlled design
The surface temperature obtained through controlled design is based on energy limitation by
temperature controllers or high temperature limiters. There are no additional requirements for
temperature controllers and high temperature limiters beyond those of the general industrial
standards.
NOTE Typical general industrial requirements for temperature controllers and high temperature limiters can be
found in the following documents. It is not a requirement of this document that conformity to those standards be
verified.
a) IEC 61010-1, Electrical Equipment for Measurement, Control, and Laboratory Use – Part 1: General requirements
[7];
b) IEC 60730-2-9, Automatic electrical controls – Part 2-9: Particular requirements for temperature sensing
control [8];
c) UL 508, Industrial Controls [9];
d) CSA C22.2 No. 14, Industrial control equipment [10];
e) CSA C22.2 No. 24, Temperature Indicating and Regulating Equipment [11].
– 16 – IEC/IEEE 62395-1:2024 © IEC/IEEE 2024
4.4.4 Controls and monitoring for fire sprinkler systems and safety showers
4.4.4.1 General
Temperature controllers and high temperature limiters for fire sprinkler systems and safety
showers shall comply with 4.4.4.2 and 4.4.4.3.
Testing requirements for trace heaters and control systems for use with fire sprinkler systems
are given in 5.6.
4.4.4.2 Control systems requirements
Temperature controllers and high temperature limi
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